When a foot perspires, the shoe interior can grow humid. To prevent this, air permeability within a shoe can be improved. For example, a shoe of Laid-open Japanese Patent Application H3-236801 is configured such that a sole is made partly hollow to form a recess, vent grooves communicating from the recess to the lateral surfaces of the sole are formed, and air-permeable objects are accommodated in the recess. Humidity accumulated in the recess is discharged from the vent grooves by a pumping action induced during walking.
Also, a shoe of Japanese Utility Model Registration No. 3080904 is configured such that on the sole upper surface, an elastic tube is provided, a conduit is connected to one end of the tube, and the conduit extends to the lateral surfaces of the sole. On the tube, vent holes are provided so that when the tube is pressed, air flows in and out of the tube.
With a constitution as in Laid-open Japanese Patent Application H3-236801, sufficient pumping action cannot be attained, so air inside the shoe is not discharged. With a constitution as in Japanese Utility Model Registration No. 3080904, because a tube is disposed from the toe tip to the heel, the position at which a load is applied with respect to the tube changes during walking. When the undersurface of a foot separates from the tube, air inside the tube is discharged from sections on which no load is applied into the shoe interior, so that no air is discharged outside of the shoe. Thus, both patents are insufficient for ventilating the shoe interior, and have inferior air permeability.